Objective: in this research, we studied changings and modulations of alexithymia [defined by Difficulties in Identifying Feelings (DIF); in Discussing Feelings (DDF) and by an Externally-Oriented Thinking ... [more ▼]

Objective: in this research, we studied changings and modulations of alexithymia [defined by Difficulties in Identifying Feelings (DIF); in Discussing Feelings (DDF) and by an Externally-Oriented Thinking (EOT)]. The purpose was to investigate if Day Psychiatric Hospitalization (DPH) could promote significant improvements on difficulties linked to alexithymia in a population of mood disorders patients (N = 73). Methods & results: a first study showed significant reductions of alexithymia scores. Considered as a personality trait, alexithymia’s changings lead us to promote the relative stability hypothesis, by displaying that moderate to high correlational levels were achieved. A second study revealed the variables impacting significantly on alexithymia. The selected variables were: demographic (i.e. gender; age; number of days of treatment); MMPI-2 variables; and perceived social support (assessed with the MSPSS scale). We found notably a positive effect of perceived social support (PSS) that reduced difficulties associated to alexithymia and other variables that increased alexithymia levels (e.g. antisocial practices, negative attitude to treatment). Conclusion: positive effects of PSS are well known and two main hypotheses were already proposed to explain its effect: PSS acting directly or as a buffer on stressful events. In conclusion, at the one hand, we showed that it is possible to significantly decrease at a certain level a phenomenon such as alexithymia. At the other hand, we enlightened significant modulators of alexithymia that might help therapists to promote or avoid specific aspects for patients involved in a recovery process. [less ▲]

Estrogens are the subject of intensive researches aiming to elucidate their mechanism of action on the various tissues they target and especially on mammary gland and breast cancer. The use of ready-to ... [more ▼]

Estrogens are the subject of intensive researches aiming to elucidate their mechanism of action on the various tissues they target and especially on mammary gland and breast cancer. The use of ready-to-use slow releasing devices to administer steroids, especially estrogens, to small experimental animals remains the method of choice in terms of animal well-being and of safety for both the researcher and the animal. In this study, we evaluated and compared, in vitro and in vivo, the release kinetic of estradiol (E2) over sixty days from two different slow-releasing systems: the matrix pellet (MP) and the reservoir implant (RI). We compared the impact of these systems in three E2-sensitive mouse models : mammary gland development, human MCF7 adenocarcinoma xenograft and mouse melanoma progression. The real amount of E2 that is released from both types of devices could differ from manufacturer specifications due to inadequate release for MP and initial burst effect for RI. Compared to MP, the interindividual variability was reduced with RI thanks to a superior control of the E2 release. Depending on the dose-dependent sensitivity of the physiological or pathological readout studied, this could lead to an improvement of the statistical power of in vivo experiments and thus to a reduction of the required animal number. Altogether, our data draw attention on the importance to adequately select the slow-releasing device that is the most appropriated to a specific experiment to better fulfill the 3Rs rule (Replacement, Reduction, Refinement) related to animal welfare and protection. [less ▲]

The induction of alcohol craving and the cognitive processing of alcohol-related stimuli in alcohol-dependent patients have been reported to compete with inhibitory control and contribute to alcohol ... [more ▼]

The induction of alcohol craving and the cognitive processing of alcohol-related stimuli in alcohol-dependent patients have been reported to compete with inhibitory control and contribute to alcohol relapse. The aim of the present study is to investigate whether the induction of a craving state, using an alcohol cue exposure paradigm, influences response inhibition towards both neutral stimuli and alcohol-related stimuli in alcohol-dependent patients. Thirty-one detoxified alcohol-dependent patients were exposed to either their preferred alcoholic beverage or to a glass of water. They then performed a modified stop signal task, which used alcohol-related words, neutral words and non-words, and a lexical decision as the Go response. The alcohol-cue exposure group reported significantly higher alcohol craving and showed higher percentages of commission errors towards alcohol-related words than the control group. All participants, but especially those of the alcohol-cue exposure group, showed also shorter reaction times when alcohol words were used as targets in go trials. The induction of alcohol craving in detoxified alcohol-dependent patients increases the motivational salience value of alcohol stimuli, leading them to automatically approach alcohol-related cues and therefore impairing response inhibition towards those stimuli. [less ▲]

Purpose: In 2013, during a recent heroin-assisted treatment trial, participants in heroinassisted treatment (HAT) decreased significantly more their street heroin use than participants in oral methadone ... [more ▼]

Purpose: In 2013, during a recent heroin-assisted treatment trial, participants in heroinassisted treatment (HAT) decreased significantly more their street heroin use than participants in oral methadone treatment. After the trial, HAT was discontinued. To examine whether the treatment benefits were sustained three months after the trial, the use of street heroin by the participants was analysed in a follow-up study. Results: At the follow-up assessment, street heroin use increased in the experimental group. The two groups no longer showed a significant difference (p=0.55) in the level of street heroin use. Conclusion: A predetermined and forced end of HAT was followed by a significant increase in the level of street level use. [less ▲]

Repeated drug injections lead to sensitization of their stimulant effects in mice, a phenomenon sometimes referred to as drug psychomotor sensitization. Previous studies showed that sensitization to ... [more ▼]

Repeated drug injections lead to sensitization of their stimulant effects in mice, a phenomenon sometimes referred to as drug psychomotor sensitization. Previous studies showed that sensitization to cocaine is context dependent as its expression is reduced in an environment that was not paired with cocaine administration. In contrast, the effects of the test context on ethanol sensitization remain unclear. In the present study, female OF1 mice were repeatedly injected with 1.5 g/kg ethanol to test for both the effects of context novelty/familiarity and association on ethanol sensitization. A first group of mice was extensively pre-exposed to the test context before ethanol sensitization and ethanol injections were paired with the test context (familiar and paired group). A second group was not pre-exposed to the test context, but ethanol injections were paired with the test context (nonfamiliar and paired group). Finally, a third group of mice was not pre-exposed to the test context and ethanol was repeatedly injected in the home cage (unpaired group). Control groups were similarly exposed to the test context, but were injected with saline. In a second experiment, cocaine was used as a positive control. The same behavioral procedure was used, except that mice were injected with 10 mg/kg cocaine instead of ethanol. The results show a differential involvement of the test context in the sensitization to ethanol and cocaine. Cocaine sensitization is strongly context dependent and is not expressed in the unpaired group. In contrast, the expression of ethanol sensitization is independent of the context in which it was administered, but is strongly affected by the relative novelty/familiarity of the environment. Extensive pre-exposure to the test context prevented the expression of ethanol sensitization. One possible explanation is that expression of ethanol sensitization requires an arousing environment. [less ▲]

Repeated ethanol injections lead to a sensitization of its stimulant effects in mice. Some recent results argue against a role for ventral tegmental area (VTA) dopamine neurons in ethanol behavioral ... [more ▼]

Repeated ethanol injections lead to a sensitization of its stimulant effects in mice. Some recent results argue against a role for ventral tegmental area (VTA) dopamine neurons in ethanol behavioral sensitization. The aim of the present study was to test whether in vivo ethanol locomotor sensitization correlates with changes in either basal- or ethanol evoked firing rates of dopamine neurons in vitro. Female Swiss mice were daily injected with 2.5 g/kg ethanol (or saline in the control group) for 7 days and their locomotor activity was recorded. At the end of the sensitization procedure, extracellular recordings were made from dopaminergic neurons in midbrain slices from these mice. Significantly higher spontaneous basal firing rates of dopamine neurons were recorded in ethanol-sensitized mice relative to control mice, but without correlations with the behavioral effects. The superfusion of sulpiride, a dopamine D2 antagonist, induced a stronger increase of dopamine neuron firing rates in ethanol-sensitized mice. This shows that the D2 feedback in dopamine neurons is preserved after chronic ethanol administration and argues against a reduced D2 feedback as an explanation for the increased dopamine neuron basal firing rates in ethanol-sensitized mice. Finally, ethanol superfusion (10–100 mM) significantly increased the firing rates of dopamine neurons and this effect was of higher magnitude in ethanol-sensitized mice. Furthermore, there were significant correlations between such a sensitization of dopamine neuron activity and ethanol behavioral sensitization. These results support the hypothesis that changes in brain dopamine neuron activity contribute to the behavioral sensitization of the stimulant effects of ethanol. [less ▲]

Rationale: In humans, novelty/sensation seeking is seen as a personality trait with a positive relationship with addiction vulnerability. In animal studies, one of the standard proce-dures to model ... [more ▼]

Rationale: In humans, novelty/sensation seeking is seen as a personality trait with a positive relationship with addiction vulnerability. In animal studies, one of the standard proce-dures to model novelty seeking is the "response to novelty," i.e., the levels of locomotor activity in a new environment. In rodents, a positive correlation was demonstrated between the response to novelty and several effects of drugs, especially the locomotor stimulant effects of cocaine. Objectives: The present study was designed to test in mice whether the response to novelty is stable across environments and whether its relationship with the stimulant effects of cocaine is altered by environmental changes. Experiment 1 assessed the responses to novelty of the same mice in two different novel environments. Experiment 2 tested the correlation between response to novelty and acute stimulant effects of cocaine recorded in two distinct environments. Results: The results show a weak correlation only during the first 5 min of the session between the responses to novelty measured in two distinct environments. Experiment 2 demonstrates that novelty responses and stimulant effects of cocaine are positively correlated only when both behavioral responses are measured in the same environment. In contrast, the relationship between response to novelty and acute stimulant effects of cocaine is completely lost when the behavioral responses are recorded in two different environments. Conclusions: The present results question the usual interpretation of the correlation between the response to novelty and the stimulant effects of cocaine as reflecting a relationship between two underlying individual stable characteristics. [less ▲]

Background/Aims: Heroin-assisted treatment (HAT) can improve the condition of heroin addicts still using street heroin after a methadone treatment. In Belgium, a new trial compared the efficacy of a HAT ... [more ▼]

Background/Aims: Heroin-assisted treatment (HAT) can improve the condition of heroin addicts still using street heroin after a methadone treatment. In Belgium, a new trial compared the efficacy of a HAT to existing methadone maintenance treatment. Methods: In this randomised controlled trial, HAT was limited to 12 months. Participants were assessed every 3 months. They were responders if they showed improvement on the level of street heroin use, health or criminal involvement. Results: 74 participants were randomised in the trial. The experimental group (n=36) counted 30% of responders more than the control group (n=38) at each assessment point (p<0.05), except at 12 months where the difference (11%) was no longer significant (p=0.35). Still, after 12 months, participants in the experimental group reported significantly greater improvements (p<0.05) than the control group on the level of street heroin use and on the level of physical and mental health. Both groups reported significantly less criminal facts after 12 months (p<0.001), but with no significant difference between the groups. Conclusions: This trial confirms the short-term efficacy of HAT for severe heroin addicts, who already failed methadone treatment. [less ▲]